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Titolo:
Multiple levels of control regulate the yeast cAMP-response element-binding protein repressor Sko1p in response to stress
Autore:
Pascual-Ahuir, A; Posas, F; Serrano, R; Proft, M;
Indirizzi:
Univ Politecn Valencia, CSIC, Inst Biol Mol & Celular Plantas, Valencia 46022, Spain Univ Politecn Valencia Valencia Spain 46022 antas, Valencia 46022, Spain Univ Pompeu Fabra, Dept Ciencia Expt & Salut, Cell Signaling Unit, E-08003Barcelona, Spain Univ Pompeu Fabra Barcelona Spain E-08003 Unit, E-08003Barcelona, Spain
Titolo Testata:
JOURNAL OF BIOLOGICAL CHEMISTRY
fascicolo: 40, volume: 276, anno: 2001,
pagine: 37373 - 37378
SICI:
0021-9258(20011005)276:40<37373:MLOCRT>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
KINASE-A ACTIVITY; SACCHAROMYCES-CEREVISIAE; NUCLEAR-LOCALIZATION; BZIP PROTEIN; DNA-BINDING; TRANSCRIPTION; GENE; ACTIVATOR; INDUCTION; CREB;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
28
Recensione:
Indirizzi per estratti:
Indirizzo: Proft, M Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, 240 Longwood Ave, Boston, MA 02115 USA Harvard Univ 240 Longwood Ave Boston MA USA 02115 n, MA 02115 USA
Citazione:
A. Pascual-Ahuir et al., "Multiple levels of control regulate the yeast cAMP-response element-binding protein repressor Sko1p in response to stress", J BIOL CHEM, 276(40), 2001, pp. 37373-37378

Abstract

The Sko1p transcriptional repressor regulates a subset of osmoinducible stress defense genes in Saccharomyces cerevisiae by binding to cAMP-responsive elements. We have reported previously that in response to stress Sko1p isphosphorylated by the stress-activated Hog1p mitogen-activated protein kinase, which disrupts its interaction with the Ssn6p . Tup1p corepressor. Here we report that other mechanisms are essential for the regulation of the Sko1p repressor activity upon stress. The nuclear localization of Sko1p depends on the stress-inhibited protein kinase A (PKA). Sko1p is localized in the nucleus of unstressed cells, and it redistributes to the cytosol upon severe salt stress (1 M NaCl). Yeast mutants with low PKA activity localize Sko1p to the cytoplasm in the absence of stress and exhibit deregulated expression of cAMP-responsive element-regulated genes. The central part (315-486) of Sko1p, containing the PKA phosphorylation sites and the basic domain-leucine zipper domain, is essential for its nuclear localization. Salt-induced export of Sko1p from the nucleus is independent of Hog1p and of the Bcy1p regulatory subunit of PKA. Furthermore, phosphorylation by PKA slightly enhanced DNA binding affinity of Sko1p in vitro, whereas Sko1p dimerizationin vivo is not regulated by stress. Sko1p repressor activity is associatedto its binding to the Ssn6p-Tup1p complex. Interestingly, the Sko1p NH2 terminus (1-315), containing the Hog1p phosphorylation sites, associates in vivo with Tup1p in the absence of Ssn6p, suggesting that Sko1p represses gene transcription by interacting directly with the Tup1p subunit of the Ssn6p-Tup1p complex.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 12:46:46